Early SJW actually went after Speedy Gonzales, which is why he never showed up in anything for about a decade, but real Mexicans actually like him because he really is Mexican, is a protagonist, and defies the stereotypes. So he came back.

Taco Bell dog was just "Mexican dog with Mexican accent voiced by a white guy" and actual Mexicans didn't stand up for him. The only way he could come back is either if he somehow became a positive character or just had an American accent.